The internal combustion engine shown and described in German patent document 1,300,340 shows mechanism for effecting the change in rotation direction of the internal combustion engine by use of a displaceable camshaft. For this purpose the camshaft has opposed cams for the actuation of the breathing valves in both rotation directions. An expensive control device is required for the change in rotation direction of the internal combustion engine; and additionally, all auxiliary mechanisms must be designed for both rotation directions. Such an internal combustion engine represents a compromise with respect to its optimization for performance, because the present-day requirements in this respect can only be partly satisfied.